This is an interventional, prospective, single-center study designed to collect and describe genetic, environmental and psychosocial control data from male participants. The participants did not have any prior history of cancer at the time of the oncogenetic consultation and do not have the family mutation researched during the oncogenetic consultation (targeted genetic testing). The participants are referenced in the IUCT-O medical records as family members of patients suffering from male breast cancer.

The study will be conducted on a population of 120 participants.

Inclusion Criteria:

• 1. A male volunteer participant with no personal history of cancer, registered in the IUCT-O oncogenetics database as a relative of a patient carrying a pathogenic or likely pathogenic variant in one of the cancer predisposition genes routinely analyzed at the oncogenetics laboratory
• 2. Age ≥ 66 years
• 3. Participant with no known family relationship to a patient of the MATADOR1 cohort
• 4. Participant who has undergone an oncogenetic consultation at the IUCT-O
• 5. Participant who does not carry the familial mutation in any of the cancer predisposition genes previously tested
• 6. Participant for which an archived blood sample is available for the research in the oncogenetics laboratory
• 7. Participant having signed an informed consent form before inclusion in the study and before any study specific procedure

Exclusion Criteria:

• 1. Patient who has forfeited his/her freedom by administrative or legal award or who is under legal protection (curatorship and guardianship, protection of justice).